Sound-emitter.



S. EVERSHED & W. D. KILROY.

,SOUND IEMJTTER.

APPLICATION FILED MAY 3.1910.

1,218,934. Patented Mar. 13, 1917.

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ydney Ever-shed, 2 Willie ,R'Jfbiroy 4/04 UNITED STATES fra'rnlv'rOFFICE.

SYDNEY nvnnsnnn am) wlnmufmcxsou KILROY, or cnrswxcx, ENGLAND.

SOUND-EMITTEBQ Specification Letters latent.

Patented Mar. 13, 1917.

Application and ma a, 1910. Serial n. 559,158

"To all whom it may concern.-

Be it known that wc,,S!rm-: nY Evnusnno andVVmmn DIcKsoN KILROY, subects of the Kingof Great Britain and Ireland, and

residing at Acton Lane Works, Chiswick, in the county of Middlesex,England, have invented certain new and useful Improvements Relating toSound-Emitters.

This invention relates to the means by which electric energy isconverted into the mechanical energy of sound waves in air, water orother medium of transmission and in this specification the phrasesoundwaves means any waves propagated like waves of sound and of anyfrequency whether within the limits of a-udibility or not. It relatesmore specifically to electric vibratory motors and their application forsignaling to a distance.

The object of our invention is to produce continuous or interruptedtrains of soundwaves of considerable intensity, whlch when pr.opagatedto a distance in either air or water may be heard or detected in anyknown manner and may serve as signals or conve messages by Morse codesignaling and t e like.

Our invention in brief consists in a vibratory electric motor having afixed part here-- inafter referred to as a stator, and a mov I ablepart, hereinafter referred to as a vibrator", mechanically coupled to asoundproducingoody, hereinafter referred to as a sounder.

The invention includes the novel features of construction andarrangement of parts hereinafter described and defined by the appendedclaims, an embodiment of the invention shown in the accompanyingdrawlugs m which,-

" magnets of a two Figure 1 is a longitudinal section, and, Fig. 2 is afront elevation of the stator phase construction of motor.

Referring now particularly to this drawing which lllustrates aconstruction suitablefor two phase working the vibrator is composed oftwo laminated cores in and l, fixed at right angles toeach other in themovable frame 7'. These cores are each acted upon by one of twoelectro-magnets p and g, which are formed of laminated iron and maetized 'by the coils ac and 6b. The coi s cm 'twice the frequency of thecurrent. It is essential for efficiency that the two electromagnetsshould be fixed in such relative positions as to have no mutualinduction between their windings.

The vibratory motor is preferably arranged in a suitable containing casew, where one end of thecase. is' closed by an elastic plate g, to act asthe sounder, clamped by means of a. rings. Suitable means can beemployed to render the case watertight,- so

that the sound generator may be used below the surface when it isdesired to signal through water.

When the elasticity of the'sound generating body is insufficient to givethe mass of the vibratory system a natural frequency of vibration equalto the frequency of the alternating current, the additional 'forcerequired to compel the vibrator to work at the same frequency as thecurrent \Vullld be providedfor exampleby an idle current flowing in thealternating'current windings.

The magnitude of the additional force to be provided (and hence thestrength of the.

idle current) can be estimated, when the natural frequency of thevibratory system is knownv by means of'.the formula:

Additional tom, at its maximum value-41 cm (Ff-M), where a is theamplitude ofvibration; m

. is the mass (or equivalent mass) of the vibraare connected in seriesto the terminals 14,-

and the coils 6b are similarly connected to r the terminals 15. Onephase of atwo-phase tory system; F is the frequency of the current; andn is the natural frequency of the vibratory system. The additional forceis assumed to be a sine wave.

. It will be understood that various modifications in the structure maybe made .without departing from the spiritof our invention, which is notlimited in construction or man nor of use except as required by theappended claims.

Having nowdescribed our invention what we claim as new and desire tosecure by Letters Patent isz- 1. A sound apparatus comprising incombination a vibratory electromotor having a vibrator composed of twoarmatures c0upled together and disposed at right angles to one another,a stator comprising separate coils adapted when energized to attractalternately the respective armatures, two phase alternating currentmains'having two terminals, one set of coils being connected in serieswith one of said terminals and the other set of coils being similarlyconnected with the other terminal, a vibratory diaphragm and amechanical connection between said armatures and said diaphragm,substantially as described.

2. A sound emitting apparatus comprising I in combination a vibratoryelectromotor having a stator composed of two sets of wind in'gs, avibrator comprising a movable frame, a pair of armatures carried 1n saidframe and disposed at right angles to each other, a two'phasealternating current main having two terminals, one of said windingsbeing connected in series withone of said terminals and the otherwinding being similarly connected with the other terminal, a vibratory 5diaphragm and a rigid bar connecting said movable frame with saiddiaphragm, substantially as described.

3. A sound-emitting apparatus comprising in combination a vibratoryelectromotor hav- 30 mg a vibrator comprising a double armatu-re formedof parts disposed at right angles to one another a stator comprisingseparate coils adapted when energized to attract alternatel supp yingtwo-phase alternatin murrent to. said armatures one element of t earmature being excited from one phase and the other from the otherphase, a vibratory dia hragrn and a rigid mechanical connection saidvibrator and said diaphra m.

In testimony whereof, we a x our signatures in presence of twowitnesses.

SYDNEY EVER-SHED. WILLIE DICKSON KILROY. Witnesses: BERTRAM H. MATTHEWS,C. R. MITOHELSON.

the respective armatures, means for 35 etween 4.0

